My apologies to Mr. Shakespeare for altering one of his more famous quotes. But seriously, I seldom have a firearms class where I don’t have at least one person ask about +P ammunition.

Full disclosure: I am a real fan of +P ammo, especially in short-barreled guns chambered in 9mm, .38 Special and .380 Auto. With larger calibers, it’s less critical (but still an option).

For starters, I’m sure that most of you are probably at least familiar with +P ammunition. However, to be fair to those new to the concept, a bit of background is in order. The term “+P” (or “Plus P”) simply means higher-than-standard pressure.

All factory-loaded ammunition today follows standards set by the Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI), which publishes industry standards for acceptable chamber pressures for ammunition. While many handloaders today produce loads that far exceed SAAMI specs, our needs are different.

No surprise, we strongly discourage handloads of any kind when carrying for self-defense. Besides safety, the legal implications are serious. Why make it possible for a savvy prosecutor to ask your jury why, with all the quality factory defensive ammunition available, you “just had to have ultra-powerful homemade bullets” in your gun? Be smart. Stick with factory ammo.

Do I Need +P Ammo?

Which brings us back to the original question: Do I need +P ammunition? Basically, +P ammo has two purposes: First, it will increase the velocity (and, presumably, the effectiveness) of a round fired from a typical full-sized gun, meaning one with a 4- to 5-inch barrel. Second, +P can compensate for guns with very short barrels.

For example, in a 9mm gun with a 3- to 3.5-inch barrel, 124-grain +P ammunition will usually give velocities similar to standard 124-grain ammo fired from a full-sized gun.

Ammo labeled “+P” is available from most major manufacturers and can be safely used in any gun that is certified for use with +P ammunition by the firearms manufacturer. Most modern guns qualify. If you have any doubts, contact the gunmaker.

The .357 Magnum has no SAAMI +P designation, probably because it is already a very high-pressure load. Even when fired from a 2-inch snub-nosed revolver, most defensive .357 loads are quite effective.

Caliber +P Designation John Recommends
.380 Standard and +P
9mm Standard and +P
.40 S&W No SAAMI +P Designation 165- to 180-grain JHP;
155-grain for short-barreled
.45 ACP Standard and +P 185- to 200-grain +P for short-barreled;
200- to 230-grain for full-sized
10mm No SAAMI +P Designation
.357 Magnum No SAAMI +P Designation

Although some manufacturers (Buffalo Bore, DoubleTap) produce “heavy” versions, .40 S&W also has no SAAMI +P designation. Any quality 165- to 180-grain JHP should be effective. In short-barreled guns, the 155-grain JHP loads work well.

There is also no SAAMI +P designation for 10mm, but there are plenty of choices, from mild (Federal, Winchester, Speer) to wild (Buffalo Bore, DoubleTap, Underwood, etc.). Check with the manufacturers.

Standard and +P loadings of .45 ACP ammo are available everywhere. In short-barreled guns, I’d suggest 185- to 200-grain +P loads. In full-sized guns, standard 200- to 230-grain JHP loads work fine. After all, even plain old low-pressure “ball” ammo has been reliably stopping threats for more than 100 years.

A word of warning: Whatever ammo you choose, +P or not, if you carry an auto-pistol, you must test-fire a sufficient number of rounds to verify that it functions flawlessly. How many rounds are considered sufficient? Personally, I fire at least 50 rounds. Expensive? Yep. But what is your life worth?

Bottom line: +P ammo can give you a nice bump in power, and more “punch” is usually a good thing. The options are many. The choice is up to you.

Related Reads:
Adding Fuel to the Fire: More on the Great Ammo Debate


Federal Ammunition:
Buffalo Bore: